Scientists at the University of Central Florida used miniature laboratory systems built from human cells to test how genetic mutations linked to inherited Alzheimer’s disease affect the nervous system. The mutated motor neurons disrupted their connections to muscles, even though the model contained no brain or spinal cord. The work was published in Alzheimer’s & Dementia.
The finding suggests that movement-related symptoms seen in some Alzheimer’s patients may originate in the peripheral nervous system rather than only in the brain. Researchers noted that drugs aimed at the central nervous system may therefore fail to correct abnormalities in peripheral nerves and muscles.
The evidence comes from a human-cell lab model, not from patients, so the results are early. The study does not establish that these nerve changes appear first in people.